import { useState } from 'react'
import type { SurvivorEncounter } from '../types'

interface TransferModalProps {
  survivors: SurvivorEncounter[]
  onSubmit: (encounterIds: number[]) => void
  onSkip: () => void
  isPending: boolean
}

export function TransferModal({ survivors, onSubmit, onSkip, isPending }: TransferModalProps) {
  const [selected, setSelected] = useState<Set<number>>(
    () => new Set(survivors.map((s) => s.id)),
  )

  const toggle = (id: number) => {
    setSelected((prev) => {
      const next = new Set(prev)
      if (next.has(id)) {
        next.delete(id)
      } else {
        next.add(id)
      }
      return next
    })
  }

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center p-4">
      <div className="fixed inset-0 bg-black/50" />
      <div className="relative bg-white dark:bg-gray-800 rounded-xl shadow-xl max-w-lg w-full max-h-[90vh] overflow-y-auto">
        <div className="sticky top-0 bg-white dark:bg-gray-800 border-b border-gray-200 dark:border-gray-700 px-6 py-4 rounded-t-xl">
          <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100">
            Transfer Pokemon to Next Leg
          </h2>
          <p className="text-sm text-gray-500 dark:text-gray-400 mt-1">
            Selected Pokemon will be bred down to their base form and appear as level 1 encounters in the next leg.
          </p>
        </div>

        <div className="px-6 py-4">
          {survivors.length === 0 ? (
            <p className="text-sm text-gray-500 dark:text-gray-400 text-center py-8">
              No surviving Pokemon to transfer.
            </p>
          ) : (
            <div className="grid grid-cols-3 gap-2">
              {survivors.map((survivor) => {
                const displayPokemon = survivor.currentPokemon ?? survivor.pokemon
                const isSelected = selected.has(survivor.id)

                return (
                  <button
                    key={survivor.id}
                    type="button"
                    onClick={() => toggle(survivor.id)}
                    className={`flex flex-col items-center p-3 rounded-lg border-2 text-center transition-colors ${
                      isSelected
                        ? 'border-indigo-500 bg-indigo-50 dark:bg-indigo-900/20'
                        : 'border-gray-200 dark:border-gray-700 hover:border-gray-300 dark:hover:border-gray-600'
                    }`}
                  >
                    {displayPokemon.spriteUrl ? (
                      <img
                        src={displayPokemon.spriteUrl}
                        alt={displayPokemon.name}
                        className="w-14 h-14"
                      />
                    ) : (
                      <div className="w-14 h-14 rounded-full bg-gray-200 dark:bg-gray-600 flex items-center justify-center text-lg font-bold">
                        {displayPokemon.name[0].toUpperCase()}
                      </div>
                    )}
                    <span className="text-xs font-medium text-gray-700 dark:text-gray-300 mt-1 capitalize">
                      {survivor.nickname || displayPokemon.name}
                    </span>
                    {survivor.nickname && (
                      <span className="text-[10px] text-gray-400">
                        {displayPokemon.name}
                      </span>
                    )}
                    <span className="text-[10px] text-gray-400 mt-0.5">
                      {survivor.routeName}
                    </span>
                  </button>
                )
              })}
            </div>
          )}
        </div>

        <div className="sticky bottom-0 bg-white dark:bg-gray-800 border-t border-gray-200 dark:border-gray-700 px-6 py-4 rounded-b-xl flex items-center justify-between">
          <button
            type="button"
            onClick={onSkip}
            disabled={isPending}
            className="text-sm text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-200 disabled:opacity-50"
          >
            Skip (No Transfers)
          </button>
          <div className="flex items-center gap-3">
            <span className="text-sm text-gray-400 dark:text-gray-500">
              {selected.size}/{survivors.length} selected
            </span>
            <button
              type="button"
              disabled={selected.size === 0 || isPending}
              onClick={() => onSubmit([...selected])}
              className="px-4 py-2 bg-indigo-600 text-white rounded-lg font-medium hover:bg-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
            >
              {isPending ? 'Transferring...' : 'Transfer & Advance'}
            </button>
          </div>
        </div>
      </div>
    </div>
  )
}